From “unprecedented” flooding in the UK and South America to deadly tornadoes in the U.S. to record-breaking heat in Australia, the effect of man-made climate change on extreme weather is on display across the globe as 2015 draws to a close.

Scientists have long warned that human-caused climate change increases both the likelihood and intensity of so-called extreme weather events, which include torrential rainfall, superstorms, and droughts.

This year, the natural phenomenon known as El Niño is making the effects of man-made climate change worse, according to experts. And in reverse, climate change is exacerbating El Niño. As Common Dreams reported earlier this year, temporary warming of surface waters in the Pacific, known as El Niño, drives dramatic shifts in rainfall, temperature, and wind patterns worldwide, and can last for months or even years. In fact, Oxfam has warned, the warming of the oceans as a result of climate change may double the frequency of the most powerful El Niños.

“The specifics of what’s happening where El Niño, Arctic dynamics, and underlying warming meet are, in a word, complex, and scientists are actively discussing how things might play out,” wrote Erika Spanger-Siegfried of the Union of Concerned Scientists last week. “But the collective bottom line recognizes that global warming plays a role.”

On the ground across the world, the effects have been dire.

Hundreds have been evacuated in the wake of “biblical” flooding across northern England, while The Independent reports on Monday that UK officials “were warned by the Government’s own climate change advisers that they needed to take action to protect the increasing number of homes at high risk of flooding—but rejected the advice.”

The Daily Mail reports that Labour Party official and MP for flood-hit Leeds Central Hilary Benn said the flooding showed that the debate about climate change is over.